SPLAT!(1)                       KD2BD Software                       SPLAT!(1)



NNAAMMEE
       splat An RF SSignal PPropagation, LLoss, AAnd TTerrain analysis tool

SSYYNNOOPPSSIISS
       splat  [-t  _t_r_a_n_s_m_i_t_t_e_r___s_i_t_e_._q_t_h] [-r _r_e_c_e_i_v_e_r___s_i_t_e_._q_t_h] [-c _r_x _a_n_t_e_n_n_a
       _h_e_i_g_h_t _f_o_r _L_O_S _c_o_v_e_r_a_g_e _a_n_a_l_y_s_i_s _(_f_e_e_t_/_m_e_t_e_r_s_) _(_f_l_o_a_t_)] [-L _r_x  _a_n_t_e_n_n_a
       _h_e_i_g_h_t  _f_o_r  _L_o_n_g_l_e_y_-_R_i_c_e  _c_o_v_e_r_a_g_e _a_n_a_l_y_s_i_s _(_f_e_e_t_/_m_e_t_e_r_s_) _(_f_l_o_a_t_)] [-p
       _t_e_r_r_a_i_n___p_r_o_f_i_l_e_._e_x_t] [-e _e_l_e_v_a_t_i_o_n___p_r_o_f_i_l_e_._e_x_t] [-h _h_e_i_g_h_t___p_r_o_f_i_l_e_._e_x_t]
       [-H  _n_o_r_m_a_l_i_z_e_d___h_e_i_g_h_t___p_r_o_f_i_l_e_._e_x_t]  [-l  _L_o_n_g_l_e_y_-_R_i_c_e___p_r_o_f_i_l_e_._e_x_t] [-o
       _t_o_p_o_g_r_a_p_h_i_c___m_a_p___f_i_l_e_n_a_m_e_._p_p_m]  [-b  _c_a_r_t_o_g_r_a_p_h_i_c___b_o_u_n_d_a_r_y___f_i_l_e_n_a_m_e_._d_a_t]
       [-s  _s_i_t_e_/_c_i_t_y___d_a_t_a_b_a_s_e_._d_a_t]  [-d  _s_d_f___d_i_r_e_c_t_o_r_y___p_a_t_h] [-m _e_a_r_t_h _r_a_d_i_u_s
       _m_u_l_t_i_p_l_i_e_r _(_f_l_o_a_t_)] [-f _f_r_e_q_u_e_n_c_y _(_M_H_z_) _f_o_r _F_r_e_s_n_e_l  _z_o_n_e  _c_a_l_c_u_l_a_t_i_o_n_s
       _(_f_l_o_a_t_)]  [-R  _m_a_x_i_m_u_m _c_o_v_e_r_a_g_e _r_a_d_i_u_s _(_m_i_l_e_s_/_k_i_l_o_m_e_t_e_r_s_) _(_f_l_o_a_t_)] [-dB
       _t_h_r_e_s_h_o_l_d _b_e_y_o_n_d _w_h_i_c_h _c_o_n_t_o_u_r_s _w_i_l_l  _n_o_t  _b_e  _d_i_s_p_l_a_y_e_d]  [-gc  _g_r_o_u_n_d
       _c_l_u_t_t_e_r  _h_e_i_g_h_t _(_f_e_e_t_/_m_e_t_e_r_s_) _(_f_l_o_a_t_)] [-fz _F_r_e_s_n_e_l _z_o_n_e _c_l_e_a_r_a_n_c_e _p_e_r_-
       _c_e_n_t_a_g_e _(_d_e_f_a_u_l_t _= _6_0_)] [-ano  _a_l_p_h_a_n_u_m_e_r_i_c  _o_u_t_p_u_t  _f_i_l_e  _n_a_m_e]  [-ani
       _a_l_p_h_a_n_u_m_e_r_i_c _i_n_p_u_t _f_i_l_e _n_a_m_e] [-udt _u_s_e_r___d_e_f_i_n_e_d___t_e_r_r_a_i_n___f_i_l_e_._d_a_t] [-n]
       [-N] [-nf] [-dbm] [-ngs] [-geo] [-kml] [-gpsav] [-metric]

DDEESSCCRRIIPPTTIIOONN
       SSPPLLAATT!! is a powerful terrestrial RF propagation  and  terrain  analysis
       tool  for the spectrum between 20 MHz and 20 GHz.  SSPPLLAATT!! is free soft-
       ware, and is designed for operation on Unix  and  Linux-based  worksta-
       tions.  Redistribution and/or modification is permitted under the terms
       of the GNU General Public License, Version 2, as published by the  Free
       Software Foundation.  Adoption of SSPPLLAATT!!  source code in proprietary or
       closed-source applications is  a  violation  of  this  license  and  is
       ssttrriiccttllyy forbidden.

       SSPPLLAATT!!  is  distributed in the hope that it will be useful, but WITHOUT
       ANY WARRANTY, without even the implied warranty of  MERCHANTABILITY  or
       FITNESS  FOR  A PARTICULAR PURPOSE.  See the GNU General Public License
       for more details.

IINNTTRROODDUUCCTTIIOONN
       Applications of SSPPLLAATT!! include the visualization, design, and link bud-
       get analysis of wireless Wide Area Networks (WANs), commercial and ama-
       teur radio communication systems above 20 MHz,  microwave  links,  fre-
       quency  coordination  and  interference  studies, and the prediction of
       analog and digital terrestrial radio and television contour regions.

       SSPPLLAATT!! provides RF site engineering data such as great circle distances
       and  bearings between sites, antenna elevation angles (uptilt), depres-
       sion angles (downtilt), antenna height above mean  sea  level,  antenna
       height  above  average  terrain, bearings, distances, and elevations to
       known obstructions, Longley-Rice path attenuation, and received  signal
       strength.   In addition, the minimum antenna height requirements needed
       to clear terrain, the first Fresnel zone, and any  user-definable  per-
       centage of the first Fresnel zone are also provided.

       SSPPLLAATT!!  produces  reports, graphs, and high resolution topographic maps
       that depict line-of-sight paths, and  regional  path  loss  and  signal
       strength contours through which expected coverage areas of transmitters
       and repeater systems can be obtained.   When  performing  line-of-sight
       and  Longley-Rice  analyses in situations where multiple transmitter or
       repeater sites are employed, SSPPLLAATT!! determines  individual  and  mutual
       areas of coverage within the network specified.

IINNPPUUTT FFIILLEESS
       SSPPLLAATT!!  is  a  command-line  driven  application  and  reads input data
       through a number of data files.  Some files are mandatory for  success-
       ful  execution  of  the  program, while others are optional.  Mandatory
       files include digital elevation topography models in the form of  SPLAT
       Data  Files  (SDF files), site location files (QTH files), and Longley-
       Rice model parameter files (LRP files).  Optional  files  include  city
       location  files,  cartographic  boundary  files,  user-defined  terrain
       files, path loss input files,  antenna  radiation  pattern  files,  and
       color definition files.

SSPPLLAATT DDAATTAA FFIILLEESS
       SSPPLLAATT!! imports topographic data in the form of SPLAT Data Files (SDFs).
       These files may be generated from a number of information sources.   In
       the United States, SPLAT Data Files can be generated through U.S.  Geo-
       logical Survey Digital Elevation Models (DEMs) using  the  ppoossttddoowwnnllooaadd
       and  uussggss22ssddff  utilities  included with SSPPLLAATT!!.  USGS Digital Elevation
       Models  compatible  with  these  utilities  may  be  downloaded   from:
       _h_t_t_p_:_/_/_e_d_c_f_t_p_._c_r_._u_s_g_s_._g_o_v_/_p_u_b_/_d_a_t_a_/_D_E_M_/_2_5_0_/.

       Significantly  better  resolution  and accuracy can be obtained through
       the use of SRTM Version 2 digital  elevation  models,  especially  when
       supplemented  by USGS-derived SDF data.  These one-degree by one-degree
       models are the product of the Space  Shuttle  STS-99  Radar  Topography
       Mission,  and  are  available  for most populated regions of the Earth.
       SPLAT Data Files may be generated from 3 arc-second SRTM-3  data  using
       the  included  ssrrttmm22ssddff utility.  SRTM-3 Version 2 data may be obtained
       through anonymous  FTP  from:  _f_t_p_:_/_/_e_0_s_r_p_0_1_u_._e_c_s_._n_a_s_a_._g_o_v_:_2_1_/_s_r_t_m_/_v_e_r_-
       _s_i_o_n_2_/_S_R_T_M_3_/

       Note  that  SRTM  filenames  refer to the latitude and longitude of the
       southwest corner of the topographic dataset contained within the  file.
       Therefore,  the region of interest must lie north and east of the lati-
       tude and longitude provided in the SRTM filename.

       The ssrrttmm22ssddff utility may also be used to convert 3-arc second SRTM data
       in  Band  Interleaved  by Line (.BIL) format for use with SSPPLLAATT!!.  This
       data  is  available  via  the  web  at:   _h_t_t_p_:_/_/_s_e_a_m_l_e_s_s_._u_s_g_s_._g_o_v_/_w_e_b_-
       _s_i_t_e_/_s_e_a_m_l_e_s_s_/

       Band  Interleaved  by  Line  data must be downloaded in a very specific
       manner to be compatible  with  ssrrttmm22ssddff  and  SSPPLLAATT!!.   Please  consult
       ssrrttmm22ssddff's  documentation  for  instructions  on downloading .BIL topo-
       graphic data through the USGS's Seamless Web Site.

       Even greater resolution and accuracy can be obtained by  using  1  arc-
       second  SRTM-1  Version  2 topography data.  This data is available for
       the United States and its territories and possessions, and may be down-
       loaded from: _f_t_p_:_/_/_e_0_s_r_p_0_1_u_._e_c_s_._n_a_s_a_._g_o_v_:_2_1_/_s_r_t_m_/_v_e_r_s_i_o_n_2_/_S_R_T_M_1_/

       High  resolution SDF files for use with SSPPLLAATT!! HHDD may be generated from
       data in this format using the ssrrttmm22ssddff--hhdd utility.

       Despite the higher accuracy that SRTM data has to offer, some voids  in
       the  data  sets  exist.   When  voids  are  detected,  the ssrrttmm22ssddff and
       ssrrttmm22ssddff--hhdd utilities replace them with  corresponding  data  found  in
       uussggss22ssddff  generated  SDF files.  If USGS-derived SDF data is not avail-
       able, voids are handled through adjacent  pixel  averaging,  or  direct
       replacement.

       SPLAT Data Files contain integer value topographic elevations in meters
       referenced to mean sea level for 1-degree by 1-degree  regions  of  the
       Earth.   SDF  files  can  be  read  by SSPPLLAATT!! in either standard format
       (_._s_d_f) as generated directly by the uussggss22ssddff, ssrrttmm22ssddff, and ssrrttmm22ssddff--hhdd
       utilities,  or  in  bzip2  compressed  format (_._s_d_f_._b_z_2).  Since uncom-
       pressed files can be read slightly faster than  files  that  have  been
       compressed,  SSPPLLAATT!! searches for needed SDF data in uncompressed format
       first.  If uncompressed data cannot be located,  SSPPLLAATT!!  then  searches
       for data in bzip2 compressed format.  If no compressed SDF files can be
       found for the region requested,  SSPPLLAATT!!  assumes  the  region  is  over
       water, and will assign an elevation of sea-level to these areas.

       This  feature  of SSPPLLAATT!! makes it possible to perform path analysis not
       only over land, but also between coastal areas not represented by Digi-
       tal  Elevation  Model  data.   However, this behavior of SSPPLLAATT!!  under-
       scores the importance of having all the  SDF  files  required  for  the
       region being analyzed if meaningful results are to be expected.

SSIITTEE LLOOCCAATTIIOONN ((QQTTHH)) FFIILLEESS
       SSPPLLAATT!!  imports  site  location information of transmitter and receiver
       sites analyzed by the program from ASCII files having a _._q_t_h extension.
       QTH  files  contain  the  site's name, the site's latitude (positive if
       North of the equator, negative if  South),  the  site's  longitude  (in
       degrees West, 0 to 360 degrees, or degrees East 0 to -360 degrees), and
       the site's antenna height above ground level (AGL), each separated by a
       single line-feed character.  The antenna height is assumed to be speci-
       fied in feet unless followed by the letter _m  or  the  word  _m_e_t_e_r_s  in
       either  upper or lower case.  Latitude and longitude information may be
       expressed in either decimal format (74.6864) or degree, minute,  second
       (DMS) format (74 41 11.0).

       For  example,  a site location file describing television station WNJT-
       DT, Trenton, NJ (_w_n_j_t_-_d_t_._q_t_h) might read as follows:

               WNJT-DT
               40.2828
               74.6864
               990.00

       Each transmitter and receiver site analyzed by SSPPLLAATT!!  must  be  repre-
       sented by its own site location (QTH) file.

LLOONNGGLLEEYY--RRIICCEE PPAARRAAMMEETTEERR ((LLRRPP)) FFIILLEESS
       Longley-Rice  parameter data files are required for SSPPLLAATT!! to determine
       RF path loss, field strength, or received signal power level in  either
       point-to-point  or  area prediction mode.  Longley-Rice model parameter
       data is read from files having the same base name  as  the  transmitter
       site  QTH  file, but with a _._l_r_p extension.  SSPPLLAATT!! LRP files share the
       following format (_w_n_j_t_-_d_t_._l_r_p):

               15.000  ; Earth Dielectric Constant (Relative permittivity)
               0.005   ; Earth Conductivity (Siemens per meter)
               301.000 ; Atmospheric Bending Constant (N-units)
               647.000 ; Frequency in MHz (20 MHz to 20 GHz)
               5       ; Radio Climate (5 = Continental Temperate)
               0       ; Polarization (0 = Horizontal, 1 = Vertical)
               0.50    ; Fraction of situations (50% of locations)
               0.90    ; Fraction of time (90% of the time)
               46000.0 ; ERP in Watts (optional)

       If an LRP file corresponding to the tx_site QTH file cannot  be  found,
       SSPPLLAATT!!  scans  the  current working directory for the file "splat.lrp".
       If this file cannot be found, then default parameters will be  assigned
       by SSPPLLAATT!! and a corresponding "splat.lrp" file containing these default
       parameters will be written to the current working directory.  The  gen-
       erated "splat.lrp" file can then be edited by the user as needed.

       Typical  Earth dielectric constants and conductivity values are as fol-
       lows:
                                  Dielectric Constant  Conductivity
               Salt water       :        80                5.000
               Good ground      :        25                0.020
               Fresh water      :        80                0.010
               Marshy land      :        12                0.007
               Farmland, forest :        15                0.005
               Average ground   :        15                0.005
               Mountain, sand   :        13                0.002
               City             :         5                0.001
               Poor ground      :         4                0.001

       Radio climate codes used by SSPPLLAATT!! are as follows:

               1: Equatorial (Congo)
               2: Continental Subtropical (Sudan)
               3: Maritime Subtropical (West coast of Africa)
               4: Desert (Sahara)
               5: Continental Temperate
               6: Maritime Temperate, over land (UK and west coasts  of  US  &
       EU)
               7: Maritime Temperate, over sea

       The Continental Temperate climate is common to large land masses in the
       temperate zone, such as the United States.  For paths shorter than  100
       km, there is little difference between Continental and Maritime Temper-
       ate climates.

       The seventh and eighth parameters in the _._l_r_p file  correspond  to  the
       statistical analysis provided by the Longley-Rice model.  In this exam-
       ple, SSPPLLAATT!! will return the maximum path loss occurring 50% of the time
       (fraction of time) in 90% of situations (fraction of situations).  This
       is often denoted as F(50,90) in Longley-Rice studies.   In  the  United
       States,  an  F(50,90) criteria is typically used for digital television
       (8-level VSB modulation), while  F(50,50)  is  used  for  analog  (VSB-
       AM+NTSC) broadcasts.

       For   further   information  on  these  parameters,  see:  _h_t_t_p_:_/_/_f_l_a_t_-
       _t_o_p_._i_t_s_._b_l_d_r_d_o_c_._g_o_v_/_i_t_m_._h_t_m_l  and   _h_t_t_p_:_/_/_w_w_w_._s_o_f_t_w_r_i_g_h_t_._c_o_m_/_f_a_q_/_e_n_g_i_-
       _n_e_e_r_i_n_g_/_p_r_o_p___l_o_n_g_l_e_y___r_i_c_e_._h_t_m_l

       The  final  parameter in the _._l_r_p file corresponds to the transmitter's
       effective radiated power, and is optional.  If it is  included  in  the
       _._l_r_p file, then SSPPLLAATT!! will compute received signal strength levels and
       field strength level contours when performing Longley-Rice studies.  If
       the  parameter is omitted, path loss is computed instead.  The ERP pro-
       vided in the _._l_r_p file can be overridden by using  SSPPLLAATT!!'s  _-_e_r_p  com-
       mand-line  switch.   If the _._l_r_p file contains an ERP parameter and the
       generation of path loss rather than field strength contours is desired,
       the ERP can be assigned to zero using the _-_e_r_p switch without having to
       edit the _._l_r_p file to accomplish the same result.

CCIITTYY LLOOCCAATTIIOONN FFIILLEESS
       The names and locations of cities, tower  sites,  or  other  points  of
       interest  may  be imported and plotted on topographic maps generated by
       SSPPLLAATT!!.  SSPPLLAATT!! imports the names of cities and  locations  from  ASCII
       files  containing the location of interest's name, latitude, and longi-
       tude.  Each field is separated by a comma.  Each record is separated by
       a  single  line  feed  character.  As was the case with the _._q_t_h files,
       latitude and longitude information may be entered in either decimal  or
       degree, minute, second (DMS) format.

       For example (_c_i_t_i_e_s_._d_a_t):

               Teaneck, 40.891973, 74.014506
               Tenafly, 40.919212, 73.955892
               Teterboro, 40.859511, 74.058908
               Tinton Falls, 40.279966, 74.093924
               Toms River, 39.977777, 74.183580
               Totowa, 40.906160, 74.223310
               Trenton, 40.219922, 74.754665

       A total of five separate city data files may be imported at a time, and
       there is no limit to the size of these files.  SSPPLLAATT!! reads  city  data
       on  a  "first  come/first served" basis, and plots only those locations
       whose annotations do not conflict with annotations  of  locations  read
       earlier  in  the  current  city  data file, or in previous files.  This
       behavior minimizes clutter in SSPPLLAATT!! generated  topographic  maps,  but
       also  mandates  that important locations be placed toward the beginning
       of the first city data file, and locations less important be positioned
       further down the list or in subsequent data files.

       City  data  files  may  be  generated  manually  using any text editor,
       imported from other sources, or derived from data  available  from  the
       U.S.  Census Bureau using the cciittyyddeeccooddeerr utility included with SSPPLLAATT!!.
       Such  data  is  available  free  of  charge  via   the   Internet   at:
       _h_t_t_p_:_/_/_w_w_w_._c_e_n_s_u_s_._g_o_v_/_g_e_o_/_w_w_w_/_c_o_b_/_b_d_y___f_i_l_e_s_._h_t_m_l,  and must be in ASCII
       format.

CCAARRTTOOGGRRAAPPHHIICC BBOOUUNNDDAARRYY DDAATTAA FFIILLEESS
       Cartographic boundary data may also be imported to plot the  boundaries
       of cities, counties, or states on topographic maps generated by SSPPLLAATT!!.
       Such data must be of the form of  ARC/INFO  Ungenerate  (ASCII  Format)
       Metadata  Cartographic  Boundary Files, and are available from the U.S.
       Census    Bureau    via    the     Internet     at:     _h_t_t_p_:_/_/_w_w_w_._c_e_n_-
       _s_u_s_._g_o_v_/_g_e_o_/_w_w_w_/_c_o_b_/_c_o_2_0_0_0_._h_t_m_l_#_a_s_c_i_i        and        _h_t_t_p_:_/_/_w_w_w_._c_e_n_-
       _s_u_s_._g_o_v_/_g_e_o_/_w_w_w_/_c_o_b_/_p_l_2_0_0_0_._h_t_m_l_#_a_s_c_i_i.  A total of five separate carto-
       graphic  boundary files may be imported at a time.  It is not necessary
       to import state boundaries  if  county  boundaries  have  already  been
       imported.

PPRROOGGRRAAMM OOPPEERRAATTIIOONN
       SSPPLLAATT!!  is  invoked via the command-line using a series of switches and
       arguments.  Since SSPPLLAATT!! is a CPU  and  memory  intensive  application,
       this  type  of  interface  minimizes  overhead and lends itself well to
       scripted (batch) operations.  SSPPLLAATT!!'s CPU and memory scheduling prior-
       ity may be modified through the use of the Unix nniiccee command.

       The  number and type of switches passed to SSPPLLAATT!! determine its mode of
       operation and method of output data generation.  Nearly all of SSPPLLAATT!!'s
       switches may be cascaded in any order on the command line when invoking
       the program.

       Simply typing splat on the  command  line  will  return  a  summary  of
       SSPPLLAATT!!'s command line options:

                    --==[ SPLAT! v1.3.0 Available Options... ]==--

            -t txsite(s).qth (max of 4 with -c, max of 30 with -L)
            -r rxsite.qth
            -c plot coverage of TX(s) with an RX antenna at X feet/meters AGL
            -L plot path loss map of TX based on an RX at X feet/meters AGL
            -s filename(s) of city/site file(s) to import (5 max)
            -b filename(s) of cartographic boundary file(s) to import (5 max)
            -p filename of terrain profile graph to plot
            -e filename of terrain elevation graph to plot
            -h filename of terrain height graph to plot
            -H filename of normalized terrain height graph to plot
            -l filename of path loss graph to plot
            -o filename of topographic map to generate (.ppm)
            -u filename of user-defined terrain file to import
            -d sdf file directory path (overrides path in ~/.splat_path file)
            -m earth radius multiplier
            -n do not plot LOS paths in .ppm maps
            -N do not produce unnecessary site or obstruction reports
            -f frequency for Fresnel zone calculation (MHz)
            -R modify default range for -c or -L (miles/kilometers)
           -db threshold beyond which contours will not be displayed
           -nf do not plot Fresnel zones in height plots
           -fz Fresnel zone clearance percentage (default = 60)
           -gc ground clutter height (feet/meters)
          -ngs display greyscale topography as white in .ppm files
          -erp override ERP in .lrp file (Watts)
          -ano name of alphanumeric output file
          -ani name of alphanumeric input file
          -udt filename of user defined terrain input file
          -kml generate Google Earth (.kml) compatible output
          -geo generate an Xastir .geo georeference file (with .ppm output)
          -dbm plot signal power level contours rather than field strength
        -gpsav preserve gnuplot temporary working files after SPLAT! execution
       -metric employ metric rather than imperial units for all user I/O

       The command-line options for splat and splat-hd are identical.

       SSPPLLAATT!! operates in two distinct modes: _p_o_i_n_t_-_t_o_-_p_o_i_n_t  _m_o_d_e,  and  _a_r_e_a
       _p_r_e_d_i_c_t_i_o_n  _m_o_d_e.  Either a line-of-sight (LOS) or Longley-Rice Irregu-
       lar Terrain (ITM) propagation model may be invoked by the  user.   True
       Earth, four-thirds Earth, or any other user-defined Earth radius may be
       specified when performing line-of-sight analysis.

PPOOIINNTT--TTOO--PPOOIINNTT AANNAALLYYSSIISS
       SSPPLLAATT!! may be used to perform line-of-sight  terrain  analysis  between
       two specified site locations.  For example:

       splat -t tx_site.qth -r rx_site.qth

       invokes a line-of-sight terrain analysis between the transmitter speci-
       fied in _t_x___s_i_t_e_._q_t_h and receiver specified in _r_x___s_i_t_e_._q_t_h using a  True
       Earth  radius  model,  and  writes a SSPPLLAATT!! Path Analysis Report to the
       current working directory.  The report contains details of  the  trans-
       mitter  and receiver sites, and identifies the location of any obstruc-
       tions detected along the line-of-sight path.  If an obstruction can  be
       cleared  by  raising  the receive antenna to a greater altitude, SSPPLLAATT!!
       will indicate the minimum antenna height required for  a  line-of-sight
       path to exist between the transmitter and receiver locations specified.
       Note that imperial units (miles, feet) are specified unless the _-_m_e_t_r_i_c
       switch is added to SSPPLLAATT!!'s command line options:

       splat -t tx_site.qth -r rx_site.qth -metric

       If  the antenna must be raised a significant amount, this determination
       may take a few moments.  Note that the results provided are the _m_i_n_i_m_u_m
       necessary  for  a  line-of-sight path to exist, and in the case of this
       simple example, do not take Fresnel zone  clearance  requirements  into
       consideration.

       _q_t_h  extensions  are  assumed by SSPPLLAATT!! for QTH files, and are optional
       when specifying -t and -r arguments on the command-line.  SSPPLLAATT!!  auto-
       matically  reads  all SPLAT Data Files necessary to conduct the terrain
       analysis  between  the  sites  specified.   SSPPLLAATT!!   searches  for  the
       required  SDF  files  in  the  current working directory first.  If the
       needed files are not found, SSPPLLAATT!! then searches in the path  specified
       by the _-_d command-line switch:

       splat -t tx_site -r rx_site -d /cdrom/sdf/

       An  external directory path may be specified by placing a ".splat_path"
       file under the user's home directory.  This file must contain the  full
       directory  path  of  last resort to all the SDF files.  The path in the
       _$_H_O_M_E_/_._s_p_l_a_t___p_a_t_h file must be of the form of a single  line  of  ASCII
       text:

       /opt/splat/sdf/

       and can be generated using any text editor.

       A  graph  of  the  terrain profile between the receiver and transmitter
       locations as a function of distance from the receiver can be  generated
       by adding the _-_p switch:

       splat -t tx_site -r rx_site -p terrain_profile.png

       SSPPLLAATT!!  invokes ggnnuupplloott when generating graphs.  The filename extension
       specified to SSPPLLAATT!! determines the format of the graph produced.   _._p_n_g
       will produce a 640x480 color PNG graphic file, while _._p_s or _._p_o_s_t_s_c_r_i_p_t
       will produce postscript output.  Output in formats such as  GIF,  Adobe
       Illustrator, AutoCAD dxf, LaTeX, and many others are available.  Please
       consult ggnnuupplloott, and ggnnuupplloott's documentation for  details  on  all  the
       supported output formats.

       A graph of elevations subtended by the terrain between the receiver and
       transmitter as a function of distance from the receiver can  be  gener-
       ated by using the _-_e switch:

       splat -t tx_site -r rx_site -e elevation_profile.png

       The  graph  produced  using  this  switch illustrates the elevation and
       depression angles resulting from the  terrain  between  the  receiver's
       location   and  the  transmitter  site  from  the  perspective  of  the
       receiver's location.  A second trace is plotted between the  left  side
       of the graph (receiver's location) and the location of the transmitting
       antenna on the right.   This  trace  illustrates  the  elevation  angle
       required  for  a  line-of-sight  path to exist between the receiver and
       transmitter locations.  If the trace intersects the  elevation  profile
       at  any  point on the graph, then this is an indication that a line-of-
       sight path does not exist under the conditions given, and the  obstruc-
       tions  can be clearly identified on the graph at the point(s) of inter-
       section.

       A graph illustrating terrain height referenced to a line-of-sight  path
       between  the  transmitter  and  receiver  may be generated using the _-_h
       switch:

       splat -t tx_site -r rx_site -h height_profile.png

       A terrain height  plot  normalized  to  the  transmitter  and  receiver
       antenna heights can be obtained using the _-_H switch:

       splat -t tx_site -r rx_site -H normalized_height_profile.png

       A contour of the Earth's curvature is also plotted in this mode.

       The  first Fresnel Zone, and 60% of the first Fresnel Zone can be added
       to height profile graphs by adding the _-_f switch, and specifying a fre-
       quency (in MHz) at which the Fresnel Zone should be modeled:

       splat -t tx_site -r rx_site -f 439.250 -H normalized_height_profile.png

       Fresnel Zone clearances other 60% can be specified using the _-_f_z switch
       as follows:

       splat -t tx_site -r rx_site -f 439.250 -fz 75 -H height_profile2.png

       A  graph  showing  Longley-Rice  path  loss may be plotted using the _-_l
       switch:

       splat -t tx_site -r rx_site -l path_loss_profile.png

       As before, adding the _-_m_e_t_r_i_c switch forces the graphs  to  be  plotted
       using  metric  units of measure.  The _-_g_p_s_a_v switch instructs SSPPLLAATT!! to
       preserve (rather than delete) the ggnnuupplloott working files generated  dur-
       ing  SSPPLLAATT!! execution, allowing the user to edit these files and re-run
       ggnnuupplloott if desired.

       When performing a  point-to-point  analysis,  a  SSPPLLAATT!!  Path  Analysis
       Report  is  generated  in  the form of a text file with a _._t_x_t filename
       extension.  The report contains  bearings  and  distances  between  the
       transmitter  and  receiver,  as well as the free-space and Longley-Rice
       path loss for the path being analyzed.  The mode of propagation for the
       path  is  given  as  _L_i_n_e_-_o_f_-_S_i_g_h_t,  _S_i_n_g_l_e  _H_o_r_i_z_o_n,  _D_o_u_b_l_e  _H_o_r_i_z_o_n,
       _D_i_f_f_r_a_c_t_i_o_n _D_o_m_i_n_a_n_t, or _T_r_o_p_o_s_c_a_t_t_e_r _D_o_m_i_n_a_n_t.

       Distances and locations to known obstructions along  the  path  between
       transmitter  and  receiver  are  also  provided.   If the transmitter's
       effective radiated power is specified in the transmitter's  correspond-
       ing  _._l_r_p  file,  then predicted signal strength and antenna voltage at
       the receiving location is also provided in the Path Analysis Report.

       To determine the signal-to-noise (SNR) ratio at remote  location  where
       random Johnson (thermal) noise is the primary limiting factor in recep-
       tion:

       _S_N_R=_T-_N_J-_L+_G-_N_F

       where TT is the ERP of the transmitter in dBW in the  direction  of  the
       receiver,  NNJJ  is Johnson Noise in dBW (-136 dBW for a 6 MHz television
       channel), LL is the path loss provided by SSPPLLAATT!!  in dB (as  a  _p_o_s_i_t_i_v_e
       number),  GG is the receive antenna gain in dB over isotropic, and NNFF is
       the receiver noise figure in dB.

       TT may be computed as follows:

       _T=_T_I+_G_T

       where TTII is actual amount of RF power  delivered  to  the  transmitting
       antenna in dBW, GGTT is the transmitting antenna gain (over isotropic) in
       the direction of the receiver (or the horizon if the receiver  is  over
       the horizon).

       To compute how much more signal is available over the minimum to neces-
       sary to achieve a specific signal-to-noise ratio:

       _S_i_g_n_a_l__M_a_r_g_i_n=_S_N_R-_S

       where SS is the minimum required SNR ratio (15.5 dB  for  ATSC  (8-level
       VSB) DTV, 42 dB for analog NTSC television).

       A  topographic  map  may  be  generated by SSPPLLAATT!! to visualize the path
       between the transmitter and receiver sites from  yet  another  perspec-
       tive.   Topographic maps generated by SSPPLLAATT!! display elevations using a
       logarithmic  grayscale,  with  higher  elevations  represented  through
       brighter  shades  of  gray.   The  dynamic range of the image is scaled
       between the highest and lowest elevations present in the map.  The only
       exception  to  this  is sea-level, which is represented using the color
       blue.

       Topographic output is invoked using the _-_o switch:

       splat -t tx_site -r rx_site -o topo_map.ppm

       The _._p_p_m extension on the output filename is assumed by SSPPLLAATT!!, and  is
       optional.

       In  this  example,  _t_o_p_o___m_a_p_._p_p_m  will  illustrate the locations of the
       transmitter and receiver sites specified.  In addition, the great  cir-
       cle  path  between the two sites will be drawn over locations for which
       an unobstructed path exists to the transmitter at a  receiving  antenna
       height equal to that of the receiver site (specified in _r_x___s_i_t_e_._q_t_h).

       It  may  desirable to populate the topographic map with names and loca-
       tions of cities, tower sites, or other  important  locations.   A  city
       file may be passed to SSPPLLAATT!! using the _-_s switch:

       splat -t tx_site -r rx_site -s cities.dat -o topo_map

       Up  to  five separate city files may be passed to SSPPLLAATT!! at a time fol-
       lowing the _-_s switch.

       County and state boundaries may be added to the map by specifying up to
       five  U.S.  Census  Bureau  cartographic  boundary  files  using the _-_b
       switch:

       splat -t tx_site -r rx_site -b co34_d00.dat -o topo_map

       In situations where multiple transmitter sites are in use, as  many  as
       four site locations may be passed to SSPPLLAATT!! at a time for analysis:

       splat -t tx_site1 tx_site2 tx_site3 tx_site4 -r rx_site -p profile.png

       In this example, four separate terrain profiles and obstruction reports
       will be generated by SSPPLLAATT!!.  A single topographic map can be specified
       using  the  _-_o switch, and line-of-sight paths between each transmitter
       and the receiver site indicated will be produced on the  map,  each  in
       its own color.  The path between the first transmitter specified to the
       receiver will be in green, the path between the second transmitter  and
       the  receiver  will  be in cyan, the path between the third transmitter
       and the receiver will be in violet, and the  path  between  the  fourth
       transmitter and the receiver will be in sienna.

       SSPPLLAATT!!  generated topographic maps are 24-bit TrueColor Portable PixMap
       (PPM) images.  They may  be  viewed,  edited,  or  converted  to  other
       graphic  formats  by popular image viewing applications such as xxvv, TThhee
       GGIIMMPP, IImmaaggeeMMaaggiicckk, and XXPPaaiinntt.  PNG format is  highly  recommended  for
       lossless  compressed  storage  of  SSPPLLAATT!!  generated topographic output
       files.  IImmaaggeeMMaaggiicckk's command-line utility easily converts SSPPLLAATT!!'s PPM
       files to PNG format:

       convert splat_map.ppm splat_map.png

       Another  excellent  PPM  to  PNG  command-line utility is available at:
       _h_t_t_p_:_/_/_w_w_w_._l_i_b_p_n_g_._o_r_g_/_p_u_b_/_p_n_g_/_b_o_o_k_/_s_o_u_r_c_e_s_._h_t_m_l.  As a last resort, PPM
       files  may  be compressed using the bzip2 utility, and read directly by
       TThhee GGIIMMPP in this format.

       The _-_n_g_s option assigns all terrain to the color white, and can be used
       when it is desirable to generate a map that is devoid of terrain:

       splat -t tx_site -r rx_site -b co34_d00.dat -ngs -o white_map

       The  resulting  .ppm  image file can be converted to .png format with a
       transparent background using IImmaaggeeMMaaggiicckk's ccoonnvveerrtt utility:

       convert -transparent "#FFFFFF" white_map.ppm transparent_map.png

RREEGGIIOONNAALL CCOOVVEERRAAGGEE AANNAALLYYSSIISS
       SSPPLLAATT!! can analyze a transmitter or repeater site, or network of sites,
       and  predict  the  regional  coverage for each site specified.  In this
       mode, SSPPLLAATT!! can generate a topographic map  displaying  the  geometric
       line-of-sight  coverage area of the sites based on the location of each
       site and the height of receive antenna wishing to communicate with  the
       site in question.  A regional analysis may be performed by SSPPLLAATT!! using
       the _-_c switch as follows:

       splat -t tx_site -c 30.0 -s cities.dat -b co34_d00.dat -o tx_coverage

       In this example, SSPPLLAATT!! generates a topographic  map  called  _t_x___c_o_v_e_r_-
       _a_g_e_._p_p_m  that illustrates the predicted line-of-sight regional coverage
       of _t_x___s_i_t_e to receiving  locations  having  antennas  30.0  feet  above
       ground  level  (AGL).  If the _-_m_e_t_r_i_c switch is used, the argument fol-
       lowing the _-_c switch is interpreted as being in meters rather  than  in
       feet.   The  contents  of _c_i_t_i_e_s_._d_a_t are plotted on the map, as are the
       cartographic boundaries contained in the file _c_o_3_4___d_0_0_._d_a_t.

       When plotting line-of-sight  paths  and  areas  of  regional  coverage,
       SSPPLLAATT!! by default does not account for the effects of atmospheric bend-
       ing.  However, this behavior may be modified by using the Earth  radius
       multiplier (_-_m) switch:

       splat  -t  wnjt-dt  -c  30.0  -m 1.333 -s cities.dat -b counties.dat -o
       map.ppm

       An earth radius multiplier of 1.333 instructs SSPPLLAATT!! to use the  "four-
       thirds earth" model for line-of-sight propagation analysis.  Any appro-
       priate earth radius multiplier may be selected by the user.

       When performing a regional analysis, SSPPLLAATT!! generates a site report for
       each  station  analyzed.   SSPPLLAATT!!  site  reports contain details of the
       site's geographic location,  its  height  above  mean  sea  level,  the
       antenna's height above mean sea level, the antenna's height above aver-
       age terrain, and the height of the average  terrain  calculated  toward
       the bearings of 0, 45, 90, 135, 180, 225, 270, and 315 degrees azimuth.

DDEETTEERRMMIINNIINNGG MMUULLTTIIPPLLEE RREEGGIIOONNSS OOFF LLOOSS CCOOVVEERRAAGGEE
       SSPPLLAATT!! can also display line-of-sight coverage areas  for  as  many  as
       four separate transmitter sites on a common topographic map.  For exam-
       ple:

       splat -t site1 site2 site3 site4 -c 10.0 -metric -o network.ppm

       plots the regional line-of-sight coverage of site1, site2,  site3,  and
       site4  based  on  a  receive  antenna  located 10.0 meters above ground
       level.  A topographic map is then written to the file _n_e_t_w_o_r_k_._p_p_m.  The
       line-of-sight  coverage area of the transmitters are plotted as follows
       in the colors indicated (along with their corresponding RGB  values  in
       decimal):

           site1: Green (0,255,0)
           site2: Cyan (0,255,255)
           site3: Medium Violet (147,112,219)
           site4: Sienna 1 (255,130,71)

           site1 + site2: Yellow (255,255,0)
           site1 + site3: Pink (255,192,203)
           site1 + site4: Green Yellow (173,255,47)
           site2 + site3: Orange (255,165,0)
           site2 + site4: Dark Sea Green 1 (193,255,193)
           site3 + site4: Dark Turquoise (0,206,209)

           site1 + site2 + site3: Dark Green (0,100,0)
           site1 + site2 + site4: Blanched Almond (255,235,205)
           site1 + site3 + site4: Medium Spring Green (0,250,154)
           site2 + site3 + site4: Tan (210,180,140)

           site1 + site2 + site3 + site4: Gold2 (238,201,0)

       If  separate  _._q_t_h files are generated, each representing a common site
       location but a different  antenna  height,  a  single  topographic  map
       illustrating  the regional coverage from as many as four separate loca-
       tions on a single tower may be generated by SSPPLLAATT!!.

PPAATTHH LLOOSSSS AANNAALLYYSSIISS
       If the _-_c switch is replaced by a _-_L switch, a Longley-Rice  path  loss
       map for a transmitter site may be generated:

       splat -t wnjt -L 30.0 -s cities.dat -b co34_d00.dat -o path_loss_map

       In  this mode, SSPPLLAATT!! generates a multi-color map illustrating expected
       signal levels in areas surrounding the transmitter site.  A  legend  at
       the  bottom  of the map correlates each color with a specific path loss
       range in decibels.

       The _-_d_b switch allows a threshold to be set beyond which contours  will
       not  be plotted on the map.  For example, if a path loss beyond -140 dB
       is irrelevant to the survey being conducted, SSPPLLAATT!!'s  path  loss  plot
       can be constrained to the region bounded by the 140 dB attenuation con-
       tour as follows:

       splat -t wnjt-dt -L 30.0 -s  cities.dat  -b  co34_d00.dat  -db  140  -o
       plot.ppm

       The  path  loss contour threshold may be expressed as either a positive
       or negative quantity.

       The path loss analysis range may be modified to  a  user-specific  dis-
       tance  using  the  _-_R  switch.  The argument must be given in miles (or
       kilometers if the _-_m_e_t_r_i_c switch is used).  If a range wider  than  the
       generated  topographic  map  is specified, SSPPLLAATT!! will perform Longley-
       Rice path loss calculations between all four corners of the  area  pre-
       diction map.

       The  colors used to illustrate contour regions in SSPPLLAATT!! generated cov-
       erage maps may be  tailored  by  the  user  by  creating  or  modifying
       SSPPLLAATT!!'s  color  definition  files.  SSPPLLAATT!! color definition files have
       the same base name as the transmitter's  _._q_t_h  file,  but  carry  _._l_c_f,
       _._s_c_f, and _._d_c_f extensions.  If the necessary file does not exist in the
       current working when SSPPLLAATT!!  is run, a file  containing  default  color
       definition  parameters  that is suitable for manual editing by the user
       is written into the current directory.

       When a regional Longley-Rice analysis is performed  and  the  transmit-
       ter's  ERP  is not specified or is zero, a _._l_c_f path loss color defini-
       tion file corresponding to the  transmitter  site  (_._q_t_h)  is  read  by
       SSPPLLAATT!!  from the current working directory.  If a _._l_c_f file correspond-
       ing to the transmitter site is not found, then a default file  suitable
       for manual editing by the user is automatically generated by SSPPLLAATT!!.

       A  path  loss  color  definition file possesses the following structure
       (_w_n_j_t_-_d_t_._l_c_f):

        ; SPLAT! Auto-generated  Path-Loss  Color  Definition  ("wnjt-dt.lcf")
       File
        ;
        ; Format for the parameters held in this file is as follows:
        ;
        ;    dB: red, green, blue
        ;
        ; ...where "dB" is the path loss (in dB) and
        ; "red", "green", and "blue" are the corresponding RGB color
        ; definitions ranging from 0 to 255 for the region specified.
        ;
        ; The following parameters may be edited and/or expanded
        ; for future runs of SPLAT!  A total of 32 contour regions
        ; may be defined in this file.
        ;
        ;
         80: 255,   0,   0
         90: 255, 128,   0
        100: 255, 165,   0
        110: 255, 206,   0
        120: 255, 255,   0
        130: 184, 255,   0
        140:   0, 255,   0
        150:   0, 208,   0
        160:   0, 196, 196
        170:   0, 148, 255
        180:  80,  80, 255
        190:   0,  38, 255
        200: 142,  63, 255
        210: 196,  54, 255
        220: 255,   0, 255
        230: 255, 194, 204

       If the path loss is less than 80 dB, the color Red (RGB = 255, 0, 0) is
       assigned to the region.  If the path loss is greater than or  equal  to
       80  dB, but less than 90 db, then Dark Orange (255, 128, 0) is assigned
       to the region.  Orange (255, 165, 0) is assigned to  regions  having  a
       path  loss greater than or equal to 90 dB, but less than 100 dB, and so
       on.  Greyscale terrain is displayed beyond the 230 dB  path  loss  con-
       tour.

FFIIEELLDD SSTTRREENNGGTTHH AANNAALLYYSSIISS
       If the transmitter's effective radiated power (ERP) is specified in the
       transmitter's _._l_r_p file, or expressed on  the  command-line  using  the
       _-_e_r_p  switch,  field  strength contours referenced to decibels over one
       microvolt per meter (dBuV/m) rather than path loss are produced:

       splat -t wnjt-dt -L 30.0 -erp 46000 -db 30 -o plot.ppm

       The _-_d_b switch can be used in this mode as before to limit  the  extent
       to  which  field  strength  contours  are plotted.  When plotting field
       strength contours, however, the argument given is interpreted as  being
       expressed in dBuV/m.

       SSPPLLAATT!!  field  strength  color  definition  files  share a very similar
       structure to _._l_c_f files used for plotting path loss:

        ; SPLAT! Auto-generated Signal Color Definition ("wnjt-dt.scf") File
        ;
        ; Format for the parameters held in this file is as follows:
        ;
        ;    dBuV/m: red, green, blue
        ;
        ; ...where "dBuV/m" is the signal strength (in dBuV/m) and
        ; "red", "green", and "blue" are the corresponding RGB color
        ; definitions ranging from 0 to 255 for the region specified.
        ;
        ; The following parameters may be edited and/or expanded
        ; for future runs of SPLAT!  A total of 32 contour regions
        ; may be defined in this file.
        ;
        ;
        128: 255,   0,   0
        118: 255, 165,   0
        108: 255, 206,   0
         98: 255, 255,   0
         88: 184, 255,   0
         78:   0, 255,   0
         68:   0, 208,   0
         58:   0, 196, 196
         48:   0, 148, 255
         38:  80,  80, 255
         28:   0,  38, 255
         18: 142,  63, 255
          8: 140,   0, 128

       If the signal strength is greater than or equal to 128 dB over 1 micro-
       volt per meter (dBuV/m), the color Red (255, 0, 0) is displayed for the
       region.  If the signal strength is greater than or equal to 118 dBuV/m,
       but  less  than 128 dBuV/m, then the color Orange (255, 165, 0) is dis-
       played, and so on.  Greyscale terrain is  displayed  for  regions  with
       signal strengths less than 8 dBuV/m.

       Signal  strength contours for some common VHF and UHF broadcasting ser-
       vices in the United States are as follows:




              Analog Television Broadcasting
              ------------------------------
              Channels 2-6:       City Grade: >= 74 dBuV/m
                                     Grade A: >= 68 dBuV/m
                                     Grade B: >= 47 dBuV/m
              --------------------------------------------
              Channels 7-13:      City Grade: >= 77 dBuV/m
                                     Grade A: >= 71 dBuV/m
                                     Grade B: >= 56 dBuV/m
              --------------------------------------------
              Channels 14-69:   Indoor Grade: >= 94 dBuV/m
                                  City Grade: >= 80 dBuV/m
                                     Grade A: >= 74 dBuV/m
                                     Grade B: >= 64 dBuV/m

              Digital Television Broadcasting
              -------------------------------
              Channels 2-6:       City Grade: >= 35 dBuV/m
                           Service Threshold: >= 28 dBuV/m
              --------------------------------------------
              Channels 7-13:      City Grade: >= 43 dBuV/m
                           Service Threshold: >= 36 dBuV/m
              --------------------------------------------
              Channels 14-69:     City Grade: >= 48 dBuV/m
                           Service Threshold: >= 41 dBuV/m

              NOAA Weather Radio (162.400 - 162.550 MHz)
              ------------------------------------------
                         Reliable: >= 18 dBuV/m
                     Not reliable: <  18 dBuV/m
              Unlikely to receive: <  0 dBuV/m

              FM Radio Broadcasting (88.1 - 107.9 MHz)
              ----------------------------------------
              Analog Service Contour:  60 dBuV/m
              Digital Service Contour: 65 dBuV/m


RREECCEEIIVVEEDD PPOOWWEERR LLEEVVEELL AANNAALLYYSSIISS
       If the transmitter's effective radiated power (ERP) is specified in the
       transmitter's  _._l_r_p  file,  or  expressed on the command-line using the
       _-_e_r_p switch, and the _-_d_b_m switch is invoked, received power level  con-
       tours referenced to decibels over one milliwatt (dBm) are produced:

       splat -t wnjt-dt -L 30.0 -erp 46000 -dbm -db -100 -o plot.ppm

       The  _-_d_b switch can be used to limit the extent to which received power
       level contours are plotted.  When plotting power  level  contours,  the
       argument given is interpreted as being expressed in dBm.

       SSPPLLAATT!! received power level color definition files share a very similar
       structure to the color definition files described earlier, except  that
       the  power  levels  in  dBm may be either positive or negative, and are
       limited to a range between +40 dBm and -200 dBm:

        ; SPLAT! Auto-generated DBM  Signal  Level  Color  Definition  ("wnjt-
       dt.dcf") File
        ;
        ; Format for the parameters held in this file is as follows:
        ;
        ;    dBm: red, green, blue
        ;
        ; ...where "dBm" is the received signal power level between +40 dBm
        ; and -200 dBm, and "red", "green", and "blue" are the corresponding
        ;  RGB  color  definitions ranging from 0 to 255 for the region speci-
       fied.
        ;
        ; The following parameters may be edited and/or expanded
        ; for future runs of SPLAT!  A total of 32 contour regions
        ; may be defined in this file.
        ;
        ;
          +0: 255,   0,   0
         -10: 255, 128,   0
         -20: 255, 165,   0
         -30: 255, 206,   0
         -40: 255, 255,   0
         -50: 184, 255,   0
         -60:   0, 255,   0
         -70:   0, 208,   0
         -80:   0, 196, 196
         -90:   0, 148, 255
        -100:  80,  80, 255
        -110:   0,  38, 255
        -120: 142,  63, 255
        -130: 196,  54, 255
        -140: 255,   0, 255
        -150: 255, 194, 204


AANNTTEENNNNAA RRAADDIIAATTIIOONN PPAATTTTEERRNN PPAARRAAMMEETTEERRSS
       Normalized field voltage patterns for a transmitting antenna's horizon-
       tal  and  vertical planes are imported automatically into SSPPLLAATT!! when a
       path loss, field strength, or received power level coverage analysis is
       performed.   Antenna  pattern  data is read from a pair of files having
       the same base name as the transmitter and LRP files, but with  _._a_z  and
       _._e_l  extensions  for azimuth and elevation pattern files, respectively.
       Specifications regarding pattern rotation (if any) and mechanical  beam
       tilt  and  tilt  direction  (if  any)  are also contained within SSPPLLAATT!!
       antenna pattern files.

       For example, the first few lines of a SSPPLLAATT!! azimuth pattern file might
       appear as follows (_k_v_e_a_._a_z):

               183.0
               0       0.8950590
               1       0.8966406
               2       0.8981447
               3       0.8995795
               4       0.9009535
               5       0.9022749
               6       0.9035517
               7       0.9047923
               8       0.9060051

       The  first  line of the _._a_z file specifies the amount of azimuthal pat-
       tern rotation (measured clockwise in degrees from  True  North)  to  be
       applied  by SSPPLLAATT!! to the data contained in the _._a_z file.  This is fol-
       lowed by azimuth headings (0 to 360 degrees) and their associated  nor-
       malized field patterns (0.000 to 1.000) separated by whitespace.

       The  structure of SSPPLLAATT!! elevation pattern files is slightly different.
       The first line of the _._e_l file specifies the amount of mechanical  beam
       tilt  applied  to  the  antenna.   Note that a _d_o_w_n_w_a_r_d _t_i_l_t (below the
       horizon) is expressed as a _p_o_s_i_t_i_v_e _a_n_g_l_e, while an _u_p_w_a_r_d _t_i_l_t  (above
       the  horizon)  is expressed as a _n_e_g_a_t_i_v_e _a_n_g_l_e.  This data is followed
       by the azimuthal direction of the tilt, separated by whitespace.

       The remainder of the file consists of elevation angles and their corre-
       sponding  normalized  voltage radiation pattern (0.000 to 1.000) values
       separated by whitespace.  Elevation angles must  be  specified  over  a
       -10.0  to  +90.0  degree  range.  As was the convention with mechanical
       beamtilt, _n_e_g_a_t_i_v_e _e_l_e_v_a_t_i_o_n _a_n_g_l_e_s are used  to  represent  elevations
       _a_b_o_v_e  _t_h_e  _h_o_r_i_z_o_n,  while _p_o_s_i_t_i_v_e _a_n_g_l_e_s represents elevations _b_e_l_o_w
       _t_h_e _h_o_r_i_z_o_n.

       For example, the first few lines a SSPPLLAATT!! elevation pattern file  might
       appear as follows (_k_v_e_a_._e_l):

               1.1    130.0
              -10.0   0.172
              -9.5    0.109
              -9.0    0.115
              -8.5    0.155
              -8.0    0.157
              -7.5    0.104
              -7.0    0.029
              -6.5    0.109
              -6.0    0.185

       In  this  example,  the  antenna  is  mechanically  tilted downward 1.1
       degrees towards an azimuth of 130.0 degrees.

       For best results, the resolution of  azimuth  pattern  data  should  be
       specified  to  the  nearest  degree azimuth, and elevation pattern data
       resolution should be specified to the nearest  0.01  degrees.   If  the
       pattern  data specified does not reach this level of resolution, SSPPLLAATT!!
       will interpolate the values provided  to  determine  the  data  at  the
       required resolution, although this may result in a loss in accuracy.

EEXXPPOORRTTIINNGG AANNDD IIMMPPOORRTTIINNGG RREEGGIIOONNAALL CCOONNTTOOUURR DDAATTAA
       Performing  a  regional  coverage analysis based on a Longley-Rice path
       analysis can be a very time consuming process, especially if the analy-
       sis  is  performed  repeatedly  to  discover  what effects changes to a
       transmitter's antenna radiation pattern make to the predicted  coverage
       area.

       This process can be expedited by exporting the contour data produced by
       SSPPLLAATT!! to an alphanumeric output _(_._a_n_o_) file.  The  data  contained  in
       this  file can then be modified to incorporate antenna pattern effects,
       and imported back into SSPPLLAATT!! to quickly produce a revised contour map.
       Depending  on  the  way in which SSPPLLAATT!! is invoked, alphanumeric output
       files can describe regional path loss,  signal  strength,  or  received
       signal power levels.

       For  example, an alphanumeric output file containing path loss informa-
       tion can be generated by SSPPLLAATT!! for a receive site 30 feet above ground
       level over a 50 mile radius surrounding a transmitter site to a maximum
       path loss of 140 dB (assuming ERP is not specified in the transmitter's
       _._l_r_p file) using the following syntax:

       splat -t kvea -L 30.0 -R 50.0 -db 140 -ano pathloss.dat

       If ERP is specified in the _._l_r_p file or on the command line through the
       _-_e_r_p switch, the alphanumeric output file  will  instead  contain  pre-
       dicted  field  values  in  dBuV/m.   If the _-_d_B_m command line switch is
       used, then the alphanumeric output file  will  contain  receive  signal
       power levels in dBm.

       SSPPLLAATT!!  alphanumeric output files can exceed many hundreds of megabytes
       in size.  They contain information relating to the  boundaries  of  the
       region  they describe followed by latitudes (degrees North), longitudes
       (degrees West), azimuths (referenced to True North), elevations (to the
       first  obstruction),  followed  by  either  path loss (in dB), received
       field strength (in dBuV/m), or received signal  power  level  (in  dBm)
       wwiitthhoouutt rreeggaarrdd ttoo tthhee ttrraannssmmiittttiinngg aanntteennnnaa''ss rraaddiiaattiioonn ppaatttteerrnn.

       The  first few lines of a SSPPLLAATT!! alphanumeric output file could take on
       the following appearance (_p_a_t_h_l_o_s_s_._d_a_t):

               119, 117    ; max_west, min_west
               35, 34      ; max_north, min_north
               34.2265424, 118.0631096, 48.199, -32.747, 67.70
               34.2270358, 118.0624421, 48.199, -19.161, 73.72
               34.2275292, 118.0617747, 48.199, -13.714, 77.24
               34.2280226, 118.0611072, 48.199, -10.508, 79.74
               34.2290094, 118.0597723, 48.199, -11.806, 83.26 *
               34.2295028, 118.0591048, 48.199, -11.806, 135.47 *
               34.2299962, 118.0584373, 48.199, -15.358, 137.06 *
               34.2304896, 118.0577698, 48.199, -15.358, 149.87 *
               34.2314763, 118.0564348, 48.199, -15.358, 154.16 *
               34.2319697, 118.0557673, 48.199, -11.806, 153.42 *
               34.2324631, 118.0550997, 48.199, -11.806, 137.63 *
               34.2329564, 118.0544322, 48.199, -11.806, 139.23 *
               34.2339432, 118.0530971, 48.199, -11.806, 139.75 *
               34.2344365, 118.0524295, 48.199, -11.806, 151.01 *
               34.2349299, 118.0517620, 48.199, -11.806, 147.71 *
               34.2354232, 118.0510944, 48.199, -15.358, 159.49 *
               34.2364099, 118.0497592, 48.199, -15.358, 151.67 *

       Comments can be placed in the file if they are proceeded by a semicolon
       character.   The vviimm text editor has proven capable of editing files of
       this size.

       Note as was the case in the antenna pattern files,  negative  elevation
       angles  refer to upward tilt (above the horizon), while positive angles
       refer to downward tilt (below the horizon).  These angles refer to  the
       elevation  to  the  receiving  antenna at the height above ground level
       specified using the _-_L switch  _i_f  the  path  between  transmitter  and
       receiver  is  unobstructed.   If  the  path between the transmitter and
       receiver is obstructed, an asterisk (*) is placed on  the  end  of  the
       line,  and  the elevation angle returned by SSPPLLAATT!! refers the elevation
       angle to the first obstruction  rather  than  the  geographic  location
       specified  on  the line.  This is done in response to the fact that the
       Longley-Rice model considers the energy reaching a distant  point  over
       an  obstructed  path  to be the result of the energy scattered over the
       top of the first obstruction along the path.  Since energy cannot reach
       the  obstructed  location  directly,  the actual elevation angle to the
       destination over such a path becomes irrelevant.

       When modifying SSPPLLAATT!! path loss files to reflect antenna pattern  data,
       _o_n_l_y _t_h_e _l_a_s_t _n_u_m_e_r_i_c _c_o_l_u_m_n should be amended to reflect the antenna's
       normalized gain at the azimuth and elevation angles  specified  in  the
       file.  Programs and scripts capable of performing this task are left as
       an exercise for the user.

       Modified alphanumeric output files can be  imported  back  into  SSPPLLAATT!!
       for  generating  revised  coverage  maps provided that the ERP and -dBm
       options are used as they were when the  alphanumeric  output  file  was
       originally generated:

       splat -t kvea -ani pathloss.dat -s city.dat -b county.dat -o map.ppm

       Note  that  alphanumeric output files generated by splat cannot be used
       with splat-hd, or vice-versa  due  to  the  resolution  incompatibility
       between the two versions of the program.  Also, each of the three types
       of alphanumeric output files are incompatible with one  another,  so  a
       file  containing  path loss data cannot be imported into SSPPLLAATT!! to pro-
       duce signal strength or received power level contours, etc.

UUSSEERR--DDEEFFIINNEEDD TTEERRRRAAIINN IINNPPUUTT FFIILLEESS
       A user-defined terrain file is a user-generated  text  file  containing
       latitudes,  longitudes, and heights above ground level of specific ter-
       rain features believed to be of importance to the SSPPLLAATT!! analysis being
       conducted,  but  noticeably  absent  from  the SDF files being used.  A
       user-defined terrain file is imported into a SSPPLLAATT!! analysis using  the
       _-_u_d_t switch:

        splat -t tx_site -r rx_site -udt udt_file.txt -o map.ppm

       A user-defined terrain file has the following appearance and structure:

              40.32180556, 74.1325, 100.0 meters
              40.321805, 74.1315, 300.0
              40.3218055, 74.1305, 100.0 meters

       Terrain height is interpreted as being described in feet  above  ground
       level  unless  followed  by the word _m_e_t_e_r_s, and is added _o_n _t_o_p _o_f the
       terrain specified in the SDF data  for  the  locations  specified.   Be
       aware  that  each user-defined terrain feature specified will be inter-
       preted as being 3-arc seconds in both latitude and longitude  in  splat
       and  1  arc-second  in  latitude  and  longitude in splat-hd.  Features
       described in the user-defined  terrain  file  that  overlap  previously
       defined  features in the file are ignored by SSPPLLAATT!! to avoid ambiguity.

GGRROOUUNNDD CCLLUUTTTTEERR
       The height of ground clutter can be specified using the _-_g_c switch:

             splat -t wnjt-dt -r kd2bd -gc 30.0 -H wnjt-dt_path.png

       The _-_g_c switch as the effect of raising  the  overall  terrain  by  the
       specified  amount in feet (or meters if the _-_m_e_t_r_i_c switch is invoked),
       except over areas at sea-level and at the  transmitting  and  receiving
       antenna  locations.   Note that the addition of ground clutter does not
       necessarily modify the Longley-Rice path loss results unless the  addi-
       tional  clutter height results in a switch in the propagation mode from
       a less obstructed path to a more obstructed path (from Line Of Sight to
       Single  Horizon  Diffraction Dominant, for example).  It does, however,
       affect Fresnel zone clearances and line of sight determinations.

SSIIMMPPLLEE TTOOPPOOGGRRAAPPHHIICC MMAAPP GGEENNEERRAATTIIOONN
       In certain situations it may be desirable to generate a topographic map
       of  a  region  without plotting coverage areas, line-of-sight paths, or
       generating obstruction reports.  There are several ways of doing  this.
       If  one  wishes to generate a topographic map illustrating the location
       of a transmitter and receiver site  along  with  a  brief  text  report
       describing the locations and distances between the sites, the _-_n switch
       should be invoked as follows:

       splat -t tx_site -r rx_site -n -o topo_map.ppm

       If no text report is desired, then the _-_N switch is used:

       splat -t tx_site -r rx_site -N -o topo_map.ppm

       If a topographic map centered about a single  site  out  to  a  minimum
       specified radius is desired instead, a command similar to the following
       can be used:

       splat -t tx_site -R 50.0 -s NJ_Cities -b NJ_Counties -o topo_map.ppm

       where -R specifies the minimum radius of the map in miles  (or  kilome-
       ters  if  the  _-_m_e_t_r_i_c switch is used).  Note that the tx_site name and
       location are not displayed in this example.  If display of this  infor-
       mation  is  desired,  simply  create a SSPPLLAATT!! city file (_-_s option) and
       append it to the list of command-line options illustrated above.

       If the _-_o switch and output filename are omitted in  these  operations,
       topographic  output  is written to a file named _t_x___s_i_t_e_._p_p_m in the cur-
       rent working directory by default.

GGEEOORREEFFEERREENNCCEE FFIILLEE GGEENNEERRAATTIIOONN
       Topographic, coverage (_-_c), and path loss contour (_-_L)  maps  generated
       by  SSPPLLAATT!!  may be imported into XXaassttiirr (X Amateur Station Tracking and
       Information Reporting) software by generating a georeference file using
       SSPPLLAATT!!'s _-_g_e_o switch:

       splat -t kd2bd -R 50.0 -s NJ_Cities -b NJ_Counties -geo -o map.ppm

       The  georeference file generated will have the same base name as the _-_o
       file specified, but have a  _._g_e_o extension, and permit proper interpre-
       tation and display of SSPPLLAATT!!'s .ppm graphics in XXaassttiirr software.

GGOOOOGGLLEE MMAAPP KKMMLL FFIILLEE GGEENNEERRAATTIIOONN
       Keyhole  Markup Language files compatible with GGooooggllee EEaarrtthh may be gen-
       erated by SSPPLLAATT!! when performing point-to-point  or  regional  coverage
       analyses by invoking the _-_k_m_l switch:

       splat -t wnjt-dt -r kd2bd -kml

       The  KML file generated will have the same filename structure as a Path
       Analysis Report for the transmitter  and  receiver  site  names  given,
       except it will carry a  _._k_m_l extension.

       Once  loaded into GGooooggllee EEaarrtthh (File --> Open), the KML file will anno-
       tate the map display with the names of  the  transmitter  and  receiver
       site  locations.   The viewpoint of the image will be from the position
       of the transmitter site looking towards the location of  the  receiver.
       The  point-to-point path between the sites will be displayed as a white
       line while the RF  line-of-sight  path  will  be  displayed  in  green.
       GGooooggllee  EEaarrtthh's  navigation  tools  allow  the user to "fly" around the
       path, identify landmarks, roads, and other featured content.

       When performing regional coverage analysis, the  _._k_m_l file generated by
       SSPPLLAATT!!  will permit path loss or signal strength contours to be layered
       on top of GGooooggllee EEaarrtthh's display in  a  semi-transparent  manner.   The
       generated  _._k_m_l  file  will  have the same basename as that of the _._p_p_m
       file normally generated.

DDEETTEERRMMIINNAATTIIOONN OOFF AANNTTEENNNNAA HHEEIIGGHHTT AABBOOVVEE AAVVEERRAAGGEE TTEERRRRAAIINN
       SSPPLLAATT!! determines antenna height above average terrain (HAAT) according
       to  the  procedure  defined  by  Federal Communications Commission Part
       73.313(d).  According to  this  definition,  terrain  elevations  along
       eight  radials  between  2  and 10 miles (3 and 16 kilometers) from the
       site being analyzed are sampled and averaged for  each  45  degrees  of
       azimuth  starting with True North.  If one or more radials lie entirely
       over water or over land outside the United States (areas for  which  no
       USGS topography data is available), then those radials are omitted from
       the calculation of average terrain.

       Note that SRTM-3 elevation data, unlike older USGS data, extends beyond
       the  borders  of the United States.  Therefore, HAAT results may not be
       in full compliance with FCC Part 73.313(d) in areas along  the  borders
       of  the United States if the SDF files used by SSPPLLAATT!! are SRTM-derived.

       When performing point-to-point terrain analysis, SSPPLLAATT!! determines  the
       antenna  height  above  average terrain only if enough topographic data
       has already been loaded by the program to  perform  the  point-to-point
       analysis.   In  most cases, this will be true, unless the site in ques-
       tion does not lie within 10 miles of the  boundary  of  the  topography
       data in memory.

       When  performing  area  prediction  analysis, enough topography data is
       normally loaded by SSPPLLAATT!!  to  perform  average  terrain  calculations.
       Under  such  conditions,  SSPPLLAATT!!  will provide the antenna height above
       average terrain as well as the average terrain above mean sea level for
       azimuths of 0, 45, 90, 135, 180, 225, 270, and 315 degrees, and include
       such information in the generated site report.  If one or more  of  the
       eight  radials  surveyed  fall over water, or over regions for which no
       SDF data is available, SSPPLLAATT!! reports _N_o _T_e_r_r_a_i_n for the  radial  paths
       affected.

AADDDDIITTIIOONNAALL IINNFFOORRMMAATTIIOONN
       The  latest news and information regarding SSPPLLAATT!! software is available
       through  the  official   SSPPLLAATT!!   software   web   page   located   at:
       _h_t_t_p_:_/_/_w_w_w_._q_s_l_._n_e_t_/_k_d_2_b_d_/_s_p_l_a_t_._h_t_m_l.

AAUUTTHHOORRSS
       John A. Magliacane, KD2BD <_k_d_2_b_d_@_a_m_s_a_t_._o_r_g>
              Creator, Lead Developer

       Doug McDonald <_m_c_d_o_n_a_l_d_@_s_c_s_._u_i_u_c_._e_d_u>
              Original Longley-Rice Model integration

       Ron Bentley <_r_o_n_b_e_n_t_l_e_y_@_e_m_b_a_r_q_m_a_i_l_._c_o_m>
              Fresnel Zone plotting and clearance determination




KD2BD Software                 15 November 2008                      SPLAT!(1)
